Trivial: Update pypi url to new url
Trivial: Update pypi url to new url

Pypi url changed from [1] to [2]

[1] https://pypi.python.org/pypi/<package>
[2] https://pypi.org/project/<package>

Change-Id: I2abba3a89f3f89d45b97e5cc050f616136809b1d

openstack/oslo.policy